An N-type Naphthalene Diimide Ionene Polymer as Cathode Interlayer for Organic Solar Cells

Abstract

Polymer solar cells (PSCs) based on non-fullerene acceptors have the advantages of synthetic versatility, strong absorption ability, and high thermal stability. These characteristics result in impressive power conversion efficiency values, but to further push both the performance and the stability of PSCs, the insertion of appropriate interlayers in the device structure remains mandatory. Herein, a naphthalene diimide-based cathode interlayer (NDI-OH) is synthesized with a facile three-step reaction and used as a cathode interlayer for fullerene and non-fullerene PSCs. This cationic polyelectrolyte exhibited good solubility in alcohol solvents, transparency in the visible range, self-doping behavior, and good film forming ability. All these characteristics allowed the increase in the devices’ power conversion efficiencies (PCE) both for fullerene and non-fullerene-based PSCs. The successful results make NDI-OH a promising cathode interlayer to apply in PSCs.

Polymerized Naphthalimide Derivatives as Remarkable Electron‐Transport Layers for Inverted Organic Solar Cells

“…Naphthalenediimide (NDI) derivatives only present strong absorption in the band of 300-400 nm, so these ETLs can work well in both traditional OSCs [43][44][45][46][47][48] and i-OSCs. [49][50][51] Moreover, excellent ETLs for i-OSCs should possess a large thickness tolerance in order to adapt the preparing process for large-area devices. [52] However, most of organic ETLs are difficult to keep high performance once its thickness is larger than 10 nm, which is adverse to large-area processing technology.…”

“…Naphthalenediimide (NDI) derivatives only present strong absorption in the band of 300–400 nm, so these ETLs can work well in both traditional OSCs [ 43–48 ] and i‐OSCs. [ 49–51 ]…”

Advanced Progress of Organic Photovoltaics

“…This Special Issue on "Advanced progress of organic photovoltaics" includes nine papers from different groups,which refer to the theoretical research for excitons generation, charge separation and recombination of OPVs [1], the innovation of active layer materials [2][3][4] and interfacial layer materials [5], the optimization of photoelectric conversion process based on a ternary strategy [6], the investigation of encapsulation technology [7], the reviews related to film-forming kinetic process of OPVs [8], and high efficiency OPVs with PCE over 17% [9].…”

“…In addition to the synthesis and exploration of newly active layer materials, the evolution of interfacial layer materials is also crucial for the preparation of high-efficiency OPVs. In Roberto Sorrentino et al [5] the authors focused on increasing the performance of OPVs by designing and synthesizing a naphthalene diimide-based cathode interlayer (NDI-OH) with a facile three-step reaction. The NDI-OH possesses good solubility in alcohol solvents, good film-forming ability, and film thickness insensitivity, as well as self-doping properties, which makes NDI-OH suitable as a cathode interlayer.…”